Field
Exemplary embodiments relate to preparing artificial teeth through a computer aided design (CAD) or computer aided manufacturing (CAM) method by using a glass-ceramic block as an artificial-teeth material. In particular, exemplary embodiments relate to a method of bonding a high-strength zirconia post serving as a core in the glass-ceramic block. In addition, exemplary embodiments relate to a method of bonding a metal link with an implant fixture to the zirconia post and the glass-ceramic bondable to the zirconia post and a preparation method thereof.
Discussion of the Background
With economic development and increased consumer income, consumers have an increased interest in appearance. In response to consumers increased interest in appearance, researchers have increased their interest in the aesthetics of dental prosthetic materials. As a result, researchers have introduced various kinds of dental prosthetic restoration materials such as various non-metal crown materials.
Crown materials refer to prosthetic materials for restoring enamel and dentin parts of a damaged tooth. The crown materials are classified into inlay, onlay, veneer, and crown according to an applied region. Since the region restored by the crown material is the outer surface of the tooth, consumers demand that these materials closely resemble natural teeth in color, texture, and overall appearance. In addition, the crown materials must be high strength materials to prevent fracturing (e.g., abrasion and chipping). Common crown materials include aleucite glass-ceramic, a reinforced porcelain, or a fluorapatite (Ca5(PO4)3F) glass-ceramic. Although these common crown materials may closely resemble natural teeth, these materials are highly susceptible to factures. In other words, these common crown materials are low strength materials and may fracture under an applied pressure of about 80 mega pascals (MPa) to 120 MPa.
A lithium silicate glass-ceramic was introduced by Marcus P. Borom and Anna M. Turkalo. See Marcus P. Borom and Anna M. Turkalo (The Pacific Coast Regional Meeting, The American Ceramic Society, San Francisco, Calif., Oct. 31, 1973 (Glass division, No. 3-G-73P)), abstract. The formation of various crystalline nuclei and the crystalline and the strength for each growth heat treatment condition were studied by using Li2O—Al2O3—SiO2—Li2O—K2O—B2O3—P2O5-based glass. The strength of a high-temperature lithium disilicate crystalline and a low-temperature lithium metasilicate varies from 30 to 35 kPSI. The strength is caused by residual stress due to a difference in thermal expansion coefficient between base glass, mother glass, Li2SiO5, and Li2SiO3 crystals.
Materials and methods of preparing monolithic dental crowns by glass including lithium disilicate crystal are known (see European Patent No. 1 534 169 B1, filed Sep. 3, 2003). However, applying glass-ceramic material to a tri-layered block by bonding zirconia and metals is not known. The glass-ceramic material needs to be matched with the thermal expansion coefficient of zirconia, and respective inorganic bonds capable of bonding between the glass-ceramic and zirconia and between the zirconia and metal are important elements.
That is, in the related art, the glass-ceramic block is bonded with the metallic link to be applied to the implant aesthetic prosthesis, and in this case the metallic link can cause an allergic reaction with an individual having the implanted aesthetic prosthesis. Further, since the metal and the glass-ceramic are bonded with each other, fracture or bonding in an interface is not facilitated by a property difference between the two materials.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept, and, therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.